1. Technical Field
The present invention relates in general to railroad track bridge disengagement systems and, in particular, to a system, method and apparatus for mating easer rails with the uncut webs of fixed running rails at intersections with moveable railroad bridges.
2. Description of the Related Art
An easer rail system, also known as a miter rail system, permits a moveable section of railroad track to join with a fixed section of railroad track. Easer rails are used to carry wheels over a gapped joint section that is used to allow bridge movement and to compensate for thermal expansion and contraction by providing a small space between the ends of moveable and fixed rails.
Applications for easer rails include the moveable portions of railroad bridges. Some railroad bridges that are relatively close the waterway that they traverse have movable decks to allow ships to pass by or beneath them. Such bridges include vertical lift bridges, bascule bridges and swing bridges. A vertical lift bridge is similar to an elevator, as it raises and lowers a bridge deck while maintaining the deck in a horizontal orientation. A bascule bridge only lifts one end of the bridge deck, such that the bridge deck pivots about its opposite end. Finally, a swing bridge always keeps the bridge deck horizontal, but it typically rotates the bridge deck about its mid-section.
As shown in FIGS. 1-3, a conventional easer rail system provides a thermal expansion joint 10 (or gap) between the ends of a fixed rail 11 and a moveable rail 13. The joint is formed with all easer rail 15 that attaches to the fixed rail 11 and partially overlaps but freely releases the end 17 of the moveable rail 13. The ends of the easer rail 15 and the fixed rail 11 overlap each other with smooth vertical surfaces 19, 21 (FIG. 3), respectively, that are cut or machined into their respective ends. Thus, at the expansion joint 10, the track cross-section is made up of the machined moveable rail 13 and the easer rail 15, which cooperate together to provide suitable support for the rolling stock wheels of trains.
The easer rail 15 is bolted 23 directly to the mating vertical surface 21 on the fixed rail 11. Bolt holes are provided through the easer rail 15 and the vertical surface 21 of the fixed rail 11, and a bolted joint is formed between them. As best shown in FIGS. 1 and 3, the smooth vertical surface 19 of the easer rail 15 strictly interfaces with both the fixed rail 11 and the moveable rail 13. Although this design is workable, an improved system, method and apparatus for mating easer rails with fixed running rails at intersections with moveable railroad bridges would be desirable.